*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    text-decoration: none;
}

a:link{
    color: #32313a;
}

a:visited{
    color: #32313a;
}

a:hover{
    color: #32313a;
}

a:active{
    color: #32313a;
}

/* 头 */
header{
    width: 1100px;
    height: 100px;
    background-color: white;
    margin: 0 auto;
    overflow: hidden;
}

h1{
    width: 300px;
    height: 48px;
    margin-top: 26px;
    float: left;
    background-image: url("../img/01-header/codingke-icon.png");
    background-repeat: no-repeat;
    text-indent: -999px;
}

a.head{
    width: 50px;
    height: 50px;
    float: right;
    border: 15px 16px;
    background-image: url("../img/01-header/search-icon.png");
    background-repeat: no-repeat;
    margin-top: 26px; 
    background-position: 16px 15px;
    border: solid #e2e2e2 1px;
}

input.head{
    width: 294px;
    height: 50px;
    border: solid #e2e2e2 1px;
    margin-top: 26px; 
    padding-left: 10px;
    font-size: 15px;
    float: right;
}


/* nav */
nav{
    width: 100%;
    height: 59px;
    background-color: #313131;
    margin: 0 auto;
}

div.nav{
    width: 1100px;
    height: 59px;
    margin: 0 auto;
}

a.nav{
    width: 119px;
    height: 59px;
    border-right: solid #4b4b4b 2px;
    text-align: center;
    color: #f6f9f8;
    text-decoration: none;
    font-size: 15px;
    line-height: 59px;
    float: left;
}

a.nav:last-child{
    border-right: 0;
}

a.nav:first-child{
    margin-left: 15px;
}

/* main */
main{
    width: 100%;
    height: 430px;
}

main div{
    height: 430px;
    text-align: center;
}

/* 第一个s */
#s1{
    width: 1100px;
    height: 250px;
    margin:0 auto;
}

/* s1 d1 */
#s1 .d1{
    width: 487px;
    height: 250px;
    margin-right: 22px;
    float: left;
    overflow: hidden;
}

#s1 .d1 h3{
    font-size: 17px;
    padding: 37px 0px 29px;
    color: #272727;
}

#s1 .d1 li{
    font-size: 12px;
    color: #32313d;
    line-height: 22px;
    overflow: hidden;
    float: left;
}

#s1 .d1 .time{
    float: right;
    font-size: 12px;
    color: #32313d;
}

/* s1 d2 */
#s1 .d2{
    width: 349px;
    height: 250px;
    background-color: #f5f5f5;
    float: left;
}

#s1 .d2 h3{
    font-size: 16px;
    padding: 37px 26px 30px;
    color: #212121;
}

#s1 .d2 p{
    font-size: 12px;
    padding: 0px 42px 17px 26px;
    line-height: 24px;
    color: #5d5d5d;
    overflow: hidden;
}

#s1 .d2 p:last-child{
    color: #9d9d9d;
}

/* s1 d3 */
#s1 .d3{
    width: 240px;
    height: 250px;
    float: left;
}

#s1 .d3 h3{
    font-size: 18px;
    padding: 38px 26px 25px;
    color: #272727;
}

#s1 .d3 p{
    font-size: 12px;
    padding: 0px 34px 0px 26px;
    line-height: 24px;
    color: #7e7e7e;
    overflow: hidden;
}

#s1 .d3 .more{
    float: left;
    margin:58px 0 0 26px;
}

#s1 .d3 .plant{
    float: right;
}

/* 第2个s */
#s2{
    width: 100%;
    height: 288px;
    background-color: #f5f5f5;
    margin: 30px auto 0;
    overflow: hidden;
}

.s2{
    width: 1054px;
    height: 196px;
    margin:47px  auto 45px;
    background-color: white;
    overflow: hidden;
}

.s2 img{
    width: 275px;
    height: 156px;
    background-color: #d691c0;
    margin:20px;
    float: left;
}

.s2 .d2{
    width: 693px;
    height: 151px; 
    margin: 25px 35px 20px 7px;
    float: left;
}

.s2 .d2 h3{
    font-size: 18px;
    line-height: 18px;
    font-weight: 500;
    color: #3f4442;
    margin-bottom: 23px;
}

.s2 .d2 p:first-of-type{
    width: 100%;
    height: 12px;
}

.s2 .d2 #M{
    margin-right: 20px;
    vertical-align: top;
    line-height: 12px;
    font-size: 12px;
    float: left;
}

.s2 .d2 #m{
    margin-right: 44px;
    vertical-align: top;
    line-height: 12px;
    color: #29ad43;
    font-size: 12px;
    float: left;
}

.s2 .d2 a{
    font-size: 12px;
    vertical-align: top;
    line-height: 10px;
    float: left;
}

.s2 .d2 p:last-of-type{
    margin-top: 25px;
    font-size: 12px;
    line-height: 24px;
    vertical-align: top;
    color: #9f9a94;

}

/* 第3个s */
#s3{
    width: 1100px;
    height: 77px;
    overflow: hidden;
    margin: 0px auto;
    border-bottom: #dcdcdc 1px solid;
}
#s3 h3:first-of-type{
    font-size: 22px;
    margin: 36px 0 19px 4px;
    color: #3b332b;
    float: left;
}

#s3 h3:last-of-type{
    font-size: 16px;
    margin: 39px 0 19px 4px;
    color: #ed4819;
    float: right;
}

/* 第四个S */
#s4{
    width: 1100px;
    height: 290px;
    margin: 14px auto 30px;
}

#s4 div{
    width: 262px;
    height: 290px;
    background-color: #eff4f5;
    margin-right: 17px;
    float: left;
    overflow: hidden;
}

#s4 dl{
    border-bottom:solid 1px #d5dadb;
}

#s4 dl dt img{
    margin:18px 85px 16px;
}

#s4 dl dd.teacher {
    height: 15px;
    font-size: 15px;
    line-height: 15px;
    text-align: center;
    color: #2a272b;
}

#s4 dl dd.place {
    width: 142px;
    height: 26px;
    font-size: 12px;
    line-height: 26px;
    text-align: center;
    background-color: #5fa5ed;
    color: #ebeaff;
    margin: 10px auto 15px;
}

#s4 p{
    height: 69px;
    color: #5c6064;
    font-size: 10px;
    margin: 15px 28px 0 17px;
    line-height: 23px;
    vertical-align: top;
}

#s4 .d:last-child{
    margin-right: 0px;
}

footer{
    width: 1102px;
    height: 129px;
    background-color: #101c23;
    margin:0 auto;
    color: #9a9c91;
    overflow: hidden;
}

footer p{
    line-height: 24px;
    font-size: 12px;
    color: #9a9c91;
    text-align: center;
    vertical-align: top;
}

footer .p1{
    margin-top: 45px ;
}
